DAILIES AquaComfort Plus Research Articles

Chromatic dispersion of soft contact lens materials

PurposeTo investigate and evaluate the chromatic dispersion of various hydrogel and silicon hydrogel contact lens materials. MethodsEighteen different soft contact lens materials with high and low water content in lens power of −1.00 DS were measured by one operator at temperature of 20 °C ± 0.5° soaked in ISO standard phosphate-buffered saline (PBS) and in their respective packaging solutions (PS). An analogue Abbe refractometer (Model Zuzi 320, AUXILAB, S.L., Navarra, Spain) was used for refractive index (RI) measurements at 5 different wavelengths. All contact lenses were presented in a random and masked order to the operator. The Bland-Altman method with 95 % limits of agreement (LoA) and coefficient of repeatability (CoR) was used to characterise the repeatability of refractive index measurements. The Abbe numbers for each material were calculated by entering the measured and interpolated refractive indices into the Abbe number equation. One-way ANOVA analysis was used to test if there were significant differences between the 5 different wavelengths (470 nm–680 nm) within each material. An unpaired t-test was used to determine if there were differences in refractive index or dispersion between packaging solution and PBS results. ResultsNelfilcon A (Dailies Aqua Comfort Plus) soaked in PS showed the best repeatability of all 18 examined soft contact lenses across all wavelengths with an average refractive index of 1.3848 for all 6 contact lenses with a standard deviation of 0.00064. The 95 % limits of agreement were between 1.3835 and 1.3860. The mean coefficient of repeatability for nelfilcon A was 0.00125. For contact lenses soaked in ISO Standard PBS comfilcon A (Biofinity) had the best repeatability. The average refractive index of all 6 contact lenses was 1.4041 with a standard deviation of 0.00031 and a coefficient of repeatability of 0.00060. The 95 % limits of agreement were between 1.4035 and 1.4047. The analysis with One-way ANOVA with multiple comparisons involving Holm-Sidak post-hoc, showed that there are significant differences (p < 0.001, Fratio = 376.2 between wavelengths and Fratio = 1559 between different refractive indices) in the refractive index of most common lens materials across the visible wavelength range. Based on unpaired t-test, there is no significant difference (p > 0.05) in the Abbe numbers of the tested lens materials whether they have been placed in the packaging solution or in standard PBS (p > 0.05, 95 % CI = −4.8070 to 5.8680, t = 0.2054). The Abbe numbers for the calculated contact lenses soaked in PS ranged between 43.7 and 89.9. For contact lenses stored in PBS the range was between 46.3 and 81.6. ConclusionThere is a good repeatability between repeated RI measurements taken from the same lens and from the same material. The significant differences between the refractive indices across the 5 different wavelengths showed the presence of chromatic dispersion in the 18 evaluated soft contact lens materials. Furthermore, it could be shown that there is no significant difference in dispersion whether the contact lenses are soaked in standard PBS or in their respective packaging solutions. With no other published data available as a reference, absolute accuracy of the calculated Abbe numbers remains to be confirmed, however, this study did confirm that significant chromatic dispersion exists in soft contact lens materials.

Randomized Clinical Trial of Near Visual Performance with Digital Devices Using Spherical and Toric Contact Lenses.

Visual demands today incorporate a significant amount of time using digital devices. Results of this randomized crossover study of spherical and toric contact lenses demonstrated that participants were able to read smaller print size more comfortably and preferred toric contact lenses when using digital devices. The purpose of this study was to assess how toric contact lens correction affects subjective and objective outcomes of astigmatic patients using real-world digital devices. Adult participants, aged between 20 and 38 years with -0.75 to -1.50 D of astigmatism were enrolled in this double-masked randomized crossover 10-day study of Alcon Dailies Aqua Comfort Plus Sphere and Toric (Alcon, Geneva, Switzerland) contact lenses. Electronic high- and low-contrast near logMAR visual acuity and contrast sensitivity were tested. Reading performance was assessed using custom iPad applications; one used a reading sentences test, whereas the other analyzed zoom, contrast, and distance with website-based articles. Participants completed the Near Activity Visual Questionnaire and stated their preferred contact lens correction. Thirty seven participants were screened, 35 participants were enrolled, and 34 participants completed the study. Toric lens correction improved near high- and low-contrast visual acuity by 0.5 to 1 full line (P < .0001) and allowed participants to read one line smaller text on the iPad (P = .01). Participants increased the zoom 11% (P = .004) and the contrast 4% (P = .006) more with spherical lenses while reading articles. Participants held the iPad at approximately the same distance, about 33 cm (P = .63). Eighty five percent of participants preferred the toric correction (P < .0001). Participants reported improved satisfaction with toric lens correction (P = .0002) and noticed the most benefit with tasks such as reading small print and labels/instructions. This study used digital devices to demonstrate realistic benefits of toric contact lens designs for astigmatic patients.

Uptake and Release of Polyvinyl Alcohol from Hydrogel Daily Disposable Contact Lenses.

Polyvinyl alcohol is a wetting agent that could reduce the symptoms of dry eye and contact lens discomfort. Currently, only one lens type, nelfilcon A (DAILIES AquaComfort Plus), releases polyvinyl alcohol. The concept of releasing this agent from contact lenses could be applied to other lens materials. The purpose of this study was to measure the release of polyvinyl alcohol from commercially available hydrogel daily disposable contact lenses using refractive index and iodine-borate methods. Etafilcon A, omafilcon A, and nelfilcon A were soaked in phosphate-buffered saline and 0.2% trifluoroacetic acid/acetonitile for 24 hours to remove residual blister pack components. The lenses were then incubated in a 10-mg/mL solution of polyvinyl alcohol for 24 hours. After the incubation period, the lenses were placed in 2 mL of phosphate-buffered saline. At specified time intervals, t = 0.5, 1, 2, 4, 8, 12, and 24 hours, the samples were evaluated using refractive index and an iodine-borate assay. Polyvinyl alcohol uptake was determined by extracting the lenses with methanol for 24 hours. There were no differences in the uptake of polyvinyl alcohol between lens types (P > .05). The release of this wetting agent for all lens types followed a burst-plateau profile after the first 30 minutes (P > .05). Nelfilcon A had a slightly higher release of polyvinyl alcohol (P < .05) than did etafilcon A but was similar to omafilcon A (P > .05). The results suggest that the contact lenses tested in this study have similar efficiency in delivering polyvinyl alcohol.

Determination of the release of PEG and HPMC from nelfilcon A daily disposable contact lenses using a novel in vitro eye model

The traditional method to measure release of components from CLs is a vial containing a static volume of PBS (phosphate buffered saline). However, this model does not simulate physiologically relevant tear volume and natural tear flow, air exposure, and mechanical rubbing. These factors can significantly impact release kinetics. We have developed an in vitro eye model (OcuFlow) that simulates these parameters. The aim of the study was to measure the release of PEG (polyethylene glycol), and HPMC (hydroxypropyl methylcellulose) from a daily disposable hydrogel contact lens material (nelfilcon A; Dailies AquaComfort PLUS; DACP;) over 24 hrs using the OcuFlow platform. The elution of PEG and HPMC from DACP lenses was analyzed using LCMS (liquid chromatography mass spectrometry). The release of all wetting agents from the lenses followed a burst release pattern, which occurred within the first 1.5 hrs (P < 0.05). The release of PEG was greater than that of HPMC (P < 0.05). The amount of PEG and HPMC released at any given time was less than 1% of the amount in the blister pack solution. Our results suggest that HPMC and PEG are rapidly released from the CL.

Mechanical Properties of Contact Lens Materials.

To evaluate the mechanical properties of commonly available soft contact lens materials and compare results using custom-built MicroTensometer. The Young modulus, parameters for stress relaxation, and toughness of 18 types of single vision soft contact lenses were measured using custom-built MicroTensometer. Five lenses of each type were soaked in standard phosphate buffered saline and measured at a temperature of 35°C. Each lens was flattened and sliced into a rectangular strip sample using two parallel blades. The Acuvue Moist 1-Day and SofLens Daily lenses measured lowest moduli, whereas Air Optix Night & Day Aqua and Premio measured the highest. The measured moduli for silicone hydrogel materials were generally higher compared with the hydrogels except for Dailies AquaComfort Plus. The exponential curve fitted over the decay in stress showed a consistent time constant of approximately 10 sec for most lens types measured. However, the amplitude constant varied from 2.84% for SofLens Daily to 22.39% for Acuvue TruEye 1-Day. The toughness results showed that Dailies AquaComfort Plus is strong but not necessarily tough. The mechanical properties of commonly prescribed soft contact lens materials were measured using a dedicated instrument. Its reliability was demonstrated, and modulus results were compared against published data from manufacturers and other research groups. Agreement was generally good, with only a few exceptions exceeding 15% difference. The more recently released silicone hydrogel lens types have reduced modulus, approaching that of medium or high water content hydrogel materials.

Reliability of Blotting Techniques to Assess Contact Lens Water Content.

To determine the reliability of wet and modified dry blotting techniques used in the gravimetric method to assess contact lens (CL) water content (WC), the accuracy of both techniques in comparison with the nominal WC, and also their agreement. We evaluated hydrated and dry CL mass values and WC using the gravimetric method in 440 daily disposable CLs. Samples assessed corresponded to Dailies Total 1, Dailies AquaComfort Plus, 1-Day Acuvue TruEye, and Biotrue ONEday. Back vertex power ranged from +3.00 diopters (D) to -6.00 D. Within-subject coefficient of variation (CVw) and intraclass correlation coefficients were calculated. Bland-Altman analysis was also performed. The modified dry blotting technique yielded significantly (P≤0.0001) higher hydrated CL mass values. The wet blotting technique provided significantly (P≤0.04) better consistency than the modified dry one. Values of CVw for wet and modified dry blotting techniques ranged from 1.2% to 2.1% and from 3.7% to 5.4%, respectively. As for dry CL mass values, CVw values were not significantly different (P≥0.05) between wet (range: 1.1%-1.9%) and dry (range: 1.0%-5.1%) blotting techniques, except for Dailies AquaComfort Plus (P=0.03). Bland-Altman analysis showed poor agreement between the techniques. The wet blotting technique yielded WC values close (around 1%) to nominal ones, in contrast to modified dry blotting technique (≥2.5%). The wet blotting technique is not only more reliable than the modified dry one when obtaining hydrated CL mass but also provides more accurate nominal WC measurements. Agreement between the techniques was poor.

Daily disposable contact lenses versus spectacles in teenagers.

To compare clinical and subjective quality-of-life (QoL) data for teenagers wearing daily disposable contact lenses or spectacles. This open-label study randomized subjects (aged 13 to 19 years) with no previous contact lens wear experience to nelfilcon A (DAILIES AquaComfort Plus) contact lenses or spectacles for 6 months. A full clinical workup, as well as subjective QoL measures using the Pediatric Refractive Error Profile and Quality of Life Impact of Refractive Correction questionnaires, was conducted at baseline and at week 4 and months 3 and 6, with an additional study visit at week 2 for subjects randomized to wear contact lenses. A total of 110 teenagers were enrolled in the study; 13 discontinued before study completion, 10 (17.5%) from the contact lens group and 3 (5.7%) from the spectacle group (p = 0.04). Visual acuity was good for both groups at all study visits. Biomicroscopy assessments were similar at baseline for both groups. Significant differences in Pediatric Refractive Error Profile responses were noted between vision correction groups across visits for appearance (p < 0.001), satisfaction (p < 0.001), activities (p < 0.001), peer perception (p = 0.003), and overall score (p < 0.001). For Quality of Life Impact of Refractive Correction, the contact lens group gave more favorable responses than the spectacle group (p = 0.02). After 6 months of wearing contact lenses, teenagers had a more positive attitude toward comfort, vision, and safety with contact lenses. No serious adverse events were reported during the study. The daily disposable lenses used in this study are suitable for vision correction for teenagers, offering improvements in QoL measures during the first month of wear, including appearance, satisfaction, activities, and peer perceptions, without negatively impacting vision or eye health. Teenagers were able to handle contact lenses with the same amount of confidence as spectacles.

Changes in Ultraviolet Transmittance of Hydrogel and Silicone-Hydrogel Contact Lenses Induced by Wear

To evaluate the ultraviolet (UV) transmittance spectra of different contact lenses and assess the effect of wear on UV transmittance values and ocular protection factor (PF). Transmittance in the UV range (200-400 nm) of 216 contact lenses was measured before and after wear, using a spectrophotometer. The contact lenses used were ACUVUE TruEye, ACUVUE MOIST, ACUVUE OASYS, ACUVUE 2, ACUVUE DEFINE, DAILIES AquaComfort Plus, AIR OPTIX for astigmatism, FreshLook ONE-DAY lens, and Neo Cosmo. This study indicates that the following contact lenses transmitted less than the American National Standards Institute (ANSI) of 5% or less of UVB: ACUVUE DEFINE, ACUVUE MOIST, ACUVUE 2, ACUVUE TruEye, and ACUVUE OASYS. All lenses also met the ANSI standard of less than 30% transmittance of UVA except for AquaComfort Plus, AIR OPTIX for astigmatism, and Neo Cosmo. FreshLook meets the UVA transmission standard but fell short of the UVB transmission standard by 3%. FreshLook and ACUVUE MOIST had the highest calculated PF (3.9) of the hydrogel group and were unaffected after wear. Of the silicone-hydrogels (SiHs), the PF for AIR OPTIX for astigmatism was the highest (10.6) before wear and increased after wear to a PF of 13.3. The results also show that, for the UVC region, significant differences exist in transmittance values before and after wear of all SiH lenses and all hydrogel lenses, except for Neo Cosmo. FreshLook and Neo Cosmo were the only lenses that showed no statistically significant differences in the UVA transmittance after wear. Ultraviolet-blocking contact lenses were effective in blocking ultraviolet radiation to safe levels recommended by ANSI, whereas non-UV blockers such as AquaComfort Plus and AIR OPTIX for astigmatism also showed UV-attenuation capabilities greater than the values previously reported. The Neo Cosmo contact lens transmitted greater than 86% UVB and 89% UVA, making it unsuitable for UV protection seekers. Transmission is modified after contact lens wear in almost all lenses but more so in the SiH lenses, probably because of the formation of biofilms on the lens surface.

Diurnal Variations in Visual Performance for Disposable Contact Lenses

The purpose of this study is to compare the visual performance provided by different daily disposable contact lenses and to analyze its variation over time. Visual performance was evaluated in terms of visual acuity (VA) and contrast sensitivity (CS) in 15 myopic subjects (-0.50 to -4.00 diopters) who had been previously fitted with each one of the following seven types of soft contact lenses: DAILIES TOTAL1 (Alcon, Forth Worth, TX), DAILIES AquaComfort Plus (Alcon), 1-DAY ACUVUE TruEye (Johnson & Johnson Vision Care, Jacksonville, FL), 1-DAY ACUVUE MOIST (Johnson & Johnson Vision Care), SofLens daily disposable (Bausch & Lomb, Rochester, NY), Proclear 1 Day (CooperVision, Fairport, NY), and Clariti 1-Day (Sauflon, Twickenham, United Kingdom). We measured VA at three contrast levels (10%, 50%, and 100%) and CS for three spatial frequencies (10, 20, and 25 cycles/degree). These measurements were performed at 2-hr intervals during a 12-hr period of continuous wearing. Measurements were also performed with ophthalmic lenses before contact lens fitting. Two-way analysis of variance (ANOVA) results revealed significant differences across the lens types and over time for low-contrast VA only. For high- and medium-contrast VA, ophthalmic lens performed better than the contact lenses after 12 hr of use (without statistical differences among the contact lenses). Contrast sensitivity values also showed differences across lenses for the three spatial frequencies under analysis. For each particular lens type, no CS variations were observed with wearing time. Although some of the differences were not statistically significant, we found that, for many of the VA and CS measures, ophthalmic lens and DAILIES TOTAL1 yielded better values than the 1-DAY ACUVUE TruEye and Clariti 1-Day. Assessing VA at different contrasts and CS measurements allowed us to perform a visual function evaluation. Contact lens characteristics such as material and water content, among others, may be the cause of the differences in visual performance that emerged from this study. Our findings provide useful information for contact lens practitioners.

On‐eye optical quality of daily disposable contact lenses for different wearing times

To quantify the optical quality of various daily disposable contact lenses in vivo and to ascertain its variation in terms of wearing time by means of objective non-invasive determination of wavefront patterns. The crx1 adaptive-optics system was used to measure the wavefront aberrations in 15 myopic eyes before and at 2-h intervals after contact lens fitting, over a 12-h wearing period. Seven types of contact lenses having different material, water content and lens design were evaluated in this study: Dailies Total1, Dailies AquaComfort Plus, Proclear 1 Day, 1-Day Acuvue TruEye, 1-Day Acuvue moist, SofLens daily disposable and Clariti 1-Day. The aberration data were analysed by fitting Zernike polynomials up to the 5th-order for 3 and 5-mm pupils. The optical quality under each condition and at each point in time was described by means of the Root-Mean-Square (RMS) value of wavefront aberration, Modulation Transfer Function (MTF), Point Spread Function and cut-off spatial frequency. A RMS increase was observed after contact lens fitting as well as over time, both for a 3-mm and a 5-mm pupil. Each type of lens induced a different amount of wavefront aberrations, which vary over time also in a different manner. Dailies Total1 showed the lowest RMS values both at baseline and at the end of the day. In addition, Dailies Total1 provided the best MTF out of all the contact lenses that were assessed. These observations were reflected in higher cut-off spatial frequencies and visual resolution both at baseline and after 12h of wearing time. Aberrometry makes it possible to analyse accurately and in vivo the optical quality of contact lenses and to assess how lenses having different characteristics - such as material or water content - behave for different wearing times. These variations across contact lenses may result in differences in visual performance.

Comfort-Enhanced Daily Disposable Contact Lens Reduces Symptoms Among Weekly/Monthly Wear Patients

The primary objective of this trial was to explore the extent to which common contact lens-related symptoms may be improved among symptomatic daily wear contact lens wearers who habitually replaced their lenses at intervals of 1 to 4 weeks when fitted with DAILIES AquaComfort Plus for daily disposable, daily wear. Primary variables were frequency and severity of tired eyes, irritated eyes, lens awareness, blurred vision, redness, discomfort, deposits, and dryness. Eight sites, investigators enrolled 83 subjects who reported two or more of the symptoms with frequency of often or always. A sample size estimate required 60 subjects for 80% power, two-sided alpha = 0.05. Subjects were dispensed for 4 weeks of bilateral lens wear. Follow-up visits were at 2 and 4 weeks; data were collected by telephone surveys at 1 and 3 weeks. Eighty-one subjects completed the trial. Statistically significant improvements in symptom frequency were found for the symptoms of tired eyes (P<0.001), irritated eyes (P<0.001), blurred vision (P<0.001), redness (P<0.001), discomfort (P=0.024), deposits/lens needs cleaning (P<0.001), and dryness (P<0.001). Statistically significant improvements in symptom severity were found for tired eyes (P<0.001), irritated eyes (P<0.001), blurred vision (P<0.001), redness (P<0.001), discomfort (P=0.037), deposits/lens needs cleaning (P<0.001), and dryness (P<0.001). Biomicroscopy signs of limbal redness, bulbar redness, and conjunctival staining showed statistically significant improvements at 2 weeks (P=0.02, 0.01, and 0.035) and 4 weeks (P< or =0.001, 0.012, and 0.008). A range of common symptoms can be reduced and biomicroscopy signs can be improved with a comfort-enhanced daily disposable, daily wear lens, thus providing benefits that patients can experience and eye care practitioners can appreciate.

Effectiveness of moisturizing daily disposable lenses with additives

Abstract Purpose Recently, contact lens manfacturers are incorporating moisture additives in their contact lenses. Examples include povidone in 1‐DAY ACUVUE MOIST lenses, polyvinyl alcohol (PVA) in DAILIES with AquaComfort lenses and hydroxypropyl‐methylcellulose, polyethylene‐glycol and PVA in the DAILIES AquaComfort Plus lenses. These two trials were aimed to compare the effectiveness of these additives to general lens performance. Methods In the first trial, 20 investigators in the US and Germany enrolled 276 subjects currently wearing nelfilcon A with PVA (nefA+1) lenses in daily disposable modality of comparison to nelfilcon A with moisturizing additives (HPMC, PEG and PVA (nefA+3) for ten days. In the second trial, 14 investigators in Germany enrolled 314 current daily disposable wearers to wear nelfilcon A with moisturizing additives HPMC, PEG and PVA (nefA+3), and etafilcon A with added PVP (etaA+1) for one week each. Results 273 subjects completed the first trial. Comfort upon insertion was rated 9.1 for nelfilcon A with moisturizing additives (nefA+3) and 8.7 for nelfilcon A lenses (nefA+1); comfort during the day was 8.7 and 8.7, respectively; end of day comfort was 7.9 and 7.2, respectively; overall comfort was 8.6 and 8.4, respectively. 309 subjects completed the second trial. Comfort upon insertion was rated 8.6 for nefA+3 and 7.6 for etaA+1; comfort during the day was 8.4 and 7.8, respectively; end of day comfort was 7.2 and 6.6, respectively; overall comfort was 8.4 and 7.5, respectively. Conclusion Mean comfort ratings were significantly in favor of nelfilcon A with additives HPMC, PEG and PVA in both trials. Future innovations in daily disposable lenses with added moisturizes to last throughout the day should be expected. Commercial interest